Process of assembling lasts



E. O. KRENTLER Nov. 17,1925- 1,562,0 9

PROCESS OF ASSEMBLING LASTS Original Filed April 24. 1922 W 0. Z J M (44M aay.

Patented Nov. 17, 1925.

UNITED STATES PATENT OFFICE.

EDWIN 0. KItENTLER, or DETROIT, MICHIGAN, AssIeNoIt'ro KRENTLER-ABNOLD HINGE LAST COMPANY, or DErRoIT, MICHIGAN, a GORIPORATION OF MICHIGAN.

PROCESF' OF ASSEMBLING LASTS.

Original application filed April 24, 1922, steel No. 556,150. Divided 1924. Serial o. 704,506.

ings, is a specification, like letters on the drawings representing like parts.

My present invention 1s an improved process of assembling the forepart and heel part in a shoe last, and is a divisional apglication of my prior case Ser. No. 556,150,

led 'April 2 1, 1922.

An important feature of the improved last of my said prior application, wherein I have electedto claim the improved last as an article of manufacture, consists in the improved process of building the last" and assembling the wood and metallic members of the last parts. Heretofore it has been customary to put the forepart and heel part of a last, intended to be united with means for relative movement, such as the well' known types of hinge last, link lasts, slide lasts or other distinct types of connecting devices permitting relative movement of the fore and heel parts for lengthening and shortening same, in a form, jig," or the like, assembling each connecting element in its respective last part. Thereupon the. final pivot pin, rivet or the like was applied.

In my present process I am enabled to complete both the connection of the forepart and heelpart, together. with the assemblage of the unlocking and-lock releasing elements, simultaneously, and by driving in the rivet to hold same; Furthermore, I can if desired, unite the last-members by a short rivet which will not extend beyond the outside limits of the metallic parts constituting the connecting means, and thereby assemble the entire metal: hinge members, then fitting this complete unit into the last parts, driving in the pins or rivets attaching the metallic members to forepart and heel part respectively, and thus. complete the last. J'Ihis form insures the complete assembling of the unit outside the last parts, In the particular form of last herein shown,

I can follow this methodv aridlthenfldri-ve :throughthe central pivot or pin, simultaneously removing the short pin or assembling pivot.

O. KRENTLER,

and. this application'filed April 5,

Referring to the drawings, illustrating a preferred embodiment of the invention,

Fig. 1 is a side view partly in crosssection, illustrating my improved last in exten'dedposition; V

Fig. 2 is a view also partly in crosssection illustrating the last in flexed or broken position; I

Fig. 3 is a fragmentary cross-sectional view on the line 33 of Fig. 1; and I Fig. 4 is a cross-sectional view on the line 4 4 of Fig. 1. Referring to the drawings, 1 illustrates the forepart and 2 the heel part of a typical form of wooden last,fas shown in the said prior patents and my-l copending applica-, tion, preferably divided by a line of cut giving the interlocking knuckle joint effect as shownby the projecting portion 3 on the heel part 2 and the abutting bearing faces a and 5 to resist strainsfand stresses botton ward, the last being normally, in shoe manufacture, in upsidedownposition. In the forepart 1 isbored a "recess. 6 to receive a tubular member'flrthe latter being secured therein by a rivet or 'bolt 8. In the heel part is also formed a recess 9 in which a plate 10 is fitted and secured by a rivet 11. A tube 7 and plate '10.over1ap,

the tube having aslot toreceive the overlapping or projecting portion of..,sa'id plate 10, and the same are uniteduby a pivot 12 passing through the knuckleprojection 3,

7. This tubular member 7 is also formed with the. slot portion. open at I the top slightly, as illustrated at 16,- 16, Fig.4, and

metallic hinge. member comprising a pair of arms or lugsv 17, -17, suitably spaced to straddle the heel-plate 10,-being united atthe outer or top portion 20. and also at the forward part 21. Thellatter may be and preferably isformed as a blockor bolt of suitable diameter to fit slidingly the "tube 7, and may be integral with the arms 17, 17, or: secured thereto byjarivet 22. The

- arms .17 are preferably'formed in substantially triangular or V-shaped contour,

.straddling the heel plate hinge member 10 1 is my combined locking, operating and unlocking device. This device consists in a I passes.

extending downwardly each side of the plate 1O, and about the projection 15, thus olding the locking portion 21 forwardly of the pivot-12, each of said arms 17 having slots 24: through which the pivot 12 In the fore part 1 I cut or form a kerf 25 O'IESL11fiC16I1l3"ClG1)iDl1 and 'width to receive the locking and unlocking devices sofar as; the width of the arms 17, 17 is concerned, when the same ismoved forwardly, the latter sliding on the pivot 12.

1 With thelast constructedas thus far described, and in extended position as shown in Fig.1, aslight pressure on the handle portion 20 of the locking and'unloclring device will act to slide the sameforwardly for the limit allowed by the length of the slot 24: and the diameter of the pivot 12, thus moving the interlocking portion 21 out from under engagement with the over-V hanging projection 15 on the heel plate 10, thereupon permitting the heel and tore parts to be readily flexed; Upon repositioning thelast in extended position, a slight movement of the locking and unlocking device or member rearwardly or to the right viewing the figures in the drawing, serves to catch the portion 21; under the part 15 and lock the: same bearing between the lower part of the tube 7 and said part 15 of the heel Iplate. The lower contacting face of this projection, 15, Where it engages the portion '21, may'be and preferably is slightly beveled, to permit a tightening. action be," tween the contacting.' facesin thelocking action, "when; the deviceis moved tothe right, viewing the figures,- and therefore in locked, position. This perm-its conrpensa tion for looseness and wear-"and holdsthe lower faces 4; and always firm-1y "in" contact, irrespective: of a, slight jlo'oseness in the hinge parts or wear-in the rivets.

In, ordeixlto; make the locking action automatic as well as tofacilitate theaction of thesam'e, and as well, also,-, as to-maintai-n the parlts, infirm and rigidposition, I provide a coiled spring 30, fittingwithi-n'the tubular. member 7 and'bearin-g' between the rivet 8' and theinterlocking portion 21 of vthe locking and unlocking device.-

This spring 30 acts normally and con stantly to forceth'e-locking and unlocking device and particularly the portion 21 forwardly and? hence whenlit is in engagement with the projection 1 5,the last will be held under a tightening tension," the space 31 being cut back considerablyto allow for such continuous tension during a considerable extent of" such looseness inthe. wear of the last pants; I

In assembling'the last the fittings are 7 readily applied and connected, the tubular and platenhinge members being fitted and locking member, said pin passing through.

the slot 24; therein.

It will be understood that I may utilize a short pivot asindicated in dotted lines, Fig. 3, at 50,'the same terminatingat the outer surfaces of the tube 7, as shown at 51 and This enables these hinge'members to bethusassembled as a unit, then ap-v plied to the fore part 1, the retaining rivet 8 driven in, or with the tube 7 and retain. ing pivot 8 first applied to the fore part and then assembled withthe spring 30, movable locking member 21, link10 and short pivot 50 thus uniting the hinge members. Thereupon the heel part 2 is fitted and the retaining rivet 11 applied,thus completing the assemblage of the last. In the form just described, theshort tube 50 maybe concealed within the last parts, or if de-- sired, and as also herein illustrated, the longer pivot pin 12'may then be driven through, the last parts vbeing bored for this purposcas above explained, and the short pivot 50 simultaneously driven out with the driving in ofthe pivot 12. Bythis method also the last parts-areassembled-substantially "as a unit, and the connecting ele} the last isextended shown" in Fig. 1,

and thereupon the fore part and heel part are-readily flexed: and the last can be removed from the shoe. Reverse movement of the hingepartsautomatically locks the lastrin extended position, when a spring is employed, or if a spring is not employed, a slight; reverse movement ofthe locking and unlockingdevic'e serves to move the portion 21 into locked-engagement.

I believe thatmypresent invention wherein a last is devised and constructed by a process which permits the uniting; of the fore part, heel" part, and hinge members simultaneously wlth'the assembling and perinanentl-ylsecurrng of'a locking andfunlock- 'ingelementis new, and I wish to claim this "process ofimanufa cture broadly herein, this particular feature being common with the last of my present invention and my copending application, Ser. No. 553,616, filed April 17, 1922.

My invention is further described and a defined in the form of a claim as follows:

The improved method of manufacturing a last for use in the manufacture of boots and shoes, having a fore part and heel part relatively movable, which consists in con- 10 structing the forepart and heelpart with the connecting means and interlocking and releasing elements, applying the connecting, interlocking and releasing elements to the fore part and heel part while thus temporarily assembled, then completing the manufacturing operation by driving a re taining element acting to unite the last connecting and interlocking elements While simultaneously removing the temporary retaining element;

In testimony whereof, I have. signed my name to this specification.

EDWIN O. KRENTLER. 

